Red River Rising: a Top-Ten Fargo Flood in 4 of the Past 5 Years

The Red River at Fargo, North Dakota surpassed major flood level on Sunday and continues to rise, with a peak expected Wednesday at the 9th highest flood level observed since 1897. On Friday, the President an emergency declaration for North Dakota because of the flooding, and millions of sandbags have been filled in anticipation of the huge flood. This year will be the fourth time in the past five years that Fargo has experienced a top-ten flood in recorded history. Flood stage is eighteen feet, and the Red River has now reached flood stage at Fargo for an astounding nineteen of the past twenty years, according to the U.S. Army Corps of Engineers. Prior to this remarkable stretch of flooding (which began in 1993), the river flooded in just 29 of 90 years. The Army Corps of Engineers calculates that in the last twenty years, the Red River has had ten 1-in-10 year floods--one every two years, on average. Two of these floods (1997 and 2011) were greater than 1-in-50 year floods, and one (2009) was a 1-in-100 year flood. That year, the Red River hit a record high-water mark of nearly 41 feet, or 23 feet above flood stage. Thousands of people had to leave home for higher ground, and about 100 homes were badly damaged or rendered unlivable. This year's flood will be somewhere between a 1-in-10 year to 1-in-50 year flood. Since a 1-in-10 year flood, historically, has a 10% chance of occurring in a given year, the incidence of flooding along the Red River over the past twenty years has clearly been extraordinarily abnormal.

Figure 1. View of the Red River of the North at the Fargo gauge taken on April 24, 2013 (top) and April 29, 2013 (bottom.) The river rose from 17' on the 24th (flood stage is 18') to 31' on the 29th. Image credit: USGS.

Reasons for this year's flood: unfavorable weather conditionsThe USGS cites five weather factors that can act to increase flooding along the Red River. Four out of five of these factors occurred to a significant degree this year:

1) Above-normal amounts of precipitation in the fall of the year that produce high levels of soil moisture, particularly in flat surface areas, in the basin. North Dakota had its 9th wettest fall since 1895 during 2012.

2) Freezing of saturated ground in late fall or early winter, before significant snowfall occurs, that produces a hard, deep frost that limits infiltration of runoff during snowmelt. Fargo had temperatures that hit 50°F on December 2 - 3, 2012, followed by a sudden plunge to below-freezing temperatures that began on December 7. Temperatures remained below freezing the rest of December, and this froze the saturated ground to a great depth.

3) Above-normal winter snowfall in the basin. Fargo received 68.4" of snow during the winter, which is well above the city's average of 50".

4) Above-normal precipitation during snowmelt. Fargo has received 2.06" of precipitation so far this April, compared to the average of 1.23".

5) Above-normal temperatures during snowmelt. Fargo got lucky here. High temperatures in Fargo have been above average only two days during April, on the 26th and 27th.

Figure 2. Current and forecast flood stage for the Red River of the North at Fargo, ND. The river passed major flood stage on Sunday, and is headed for a crest near 35.5' (which is 17.5' above flood stage) on Wednesday. You can access images like these using our wundermap for Fargo with the "USGS River" layer turned on. Click on the icon for USGS station 05054000, then hit the "click for graph" link.

Reasons for flooding: increased urbanizationUrbanization has had a major impact on increasing flooding not only along the Red River, but in every river basin in the U.S. Many cities and developed areas are located in flood plains next to major rivers and their tributaries. Highways, streets, parking lots, sidewalks, and buildings now cover large areas of the ground that used to absorb excess rain water and slow the rate at which run-off from precipitation and melting snow reached rivers. By developing large portions of our flood plains, run-off now reaches rivers more quickly, generating higher floods.

Reasons for flooding: building more levees and flood defensesDefending ourselves against floods has made floods worse. Every time a new levee is built, or an old flood wall raised in height to prevent overtopping, more and more water is forced into the river bed, which raises the height of the flood. Flood waters that used to be able to spread out over their natural flood plains are now forbidden from spilling out over newly developed land in flood plains. For example, a 2010 proposed improvement to the flood defense system in Fargo could cause a 4 - 10 inch rise in floods immediately downstream from the city, according to the Army Corps of Engineers.

Figure 3. Peak flow of the Red River at Fargo, North Dakota from 1901 - 2012. Three of the top five floods since 1901 have occurred since 2009. The projected crest for 2013 would be the seventh greatest flood since 1897. The U.S. Army Corps of Engineers lists the 10-year flood level for the Red River at Fargo to be 10,300 cubic feet per second (cfs), and a 50-year flood to be 22,300 cfs. A 10-year flood, historically, has a 10% chance of occurring in a given year. In the last twenty years, the Red River has had ten 10-year floods--one every two years, on average. Two of these floods (1997 and 2011) were greater than 1-in-50 year floods, and one (2009) was a 1-in-100 year flood. This year will be the fourth year out of the past five with a greater than 1-in-20 year flood. Image credit: U.S. Geological Survey.

Reasons for flooding: precipitation is increasingOver the past century, precipitation over the Red River of the North drainage basin in Eastern North Dakota and Western Minnesota has increased by about 15%--more than any other region of the country. This fits the pattern expected by climate change models, which predict that winter and spring precipitation will increase by another 15% by the year 2100 over the Red River of the North drainage basin. As the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 IPCC report, water vapor in the global atmosphere has increased by about 5% over the 20th century, and 4% since 1970. Satellite measurements (Trenberth et al., 2005) have shown a 1.3% per decade increase in water vapor over the global oceans since 1988. Santer et al. (2007) used a climate model to study the relative contribution of natural and human-caused effects on increasing water vapor, and concluded that this increase was "primarily due to human-caused increases in greenhouse gases". This was also the conclusion of Willet et al. (2007).

Figure 4. The colors on the map show annual total precipitation changes (percent) for 1991-2011 compared to the 1901-1960 average, and show wetter conditions in most areas (McRoberts and Nielsen-Gammon 2011). The bars on the graphs show average precipitation differences by decade for 1901-2011 (relative to the 1901-1960 average) for each region. The far right bar is for 2001-2011. (Figure source: NOAA NCDC/CICS-NC. Data from NOAA NCDC.) Note that precipitation over the Red River of the North drainage basin in Eastern North Dakota and Western Minnesota (outlined in red) has increased by about 15%--more than any other region of the country. Image credit: National Climate Assessment Draft, 2013.

Figure 5. Projected seasonal precipitation change for winter and spring (percent) for 2071-2099 (compared to1901-1960) as projected by the climate models used to formulate the 2013 IPCC climate change report, assuming we keep emitting heat-trapping gases like carbon dioxide to the atmosphere at current rates. Teal indicates precipitation increases, and brown, decreases. Hatched areas indicate confidence that the projected changes are large and are consistently wetter or drier. In general, areas that are wet are expected to get wetter, and areas that are dry will get drier. White areas indicate confidence that the changes are small. The Red River Valley is expected to see a precipitation increase of at least 20%, which would lead to bigger and more frequent spring floods. (Figure source: NOAA NCDC / CICS-NC. Data from CMIP5; analyzed by Michael Wehner, LBNL.) Image credit: Preliminary draft of the 2013 U.S. National Climate Assessment report.

A permanent fix for Fargo's flooding problems: a $2 billion diversion canal?As the population continues to expand, development in flood plains and construction of new levees and flood protection systems will continue to push floods to higher heights. With global warming expected to continue and drive ever higher precipitation amounts--falling preferentially in heavy precipitation events--it is highly probable that flooding in the Red River Valley--and over most of the northern 1/3 of the U.S. where precipitation increases are likely (Figure 5)--will see higher and more frequent spring floods. With these higher and more frequent floods comes the increased risk of multi-billion dollar disasters, when a record flood event overwhelms flood defenses and inundates huge areas of developed flood plains. Obviously, we need to make smart decisions to limit development in flood plains to reduce the cost and suffering of these future flooding disasters.

A permanent fix for Fargo's flooding woes may lie in the construction of a 36-mile long canal that would steer flood waters around Fargo and neighboring Moorhead, Minnesota, according to an April 28, 2013 Associated Press article. The proposed canal could cost $2 billion and take ten years to complete, but has drawn strong opposition from farmers, homeowners and businesses who lie in the path of the proposed diversion channel. The http://www.redriverbasincommission.org/ has the latest long-term options on new flood control options for the Red River.

Quoting Levi32:I just noticed that the 18z GFS has a super awesome complex that looks like a convectively-coupled Kelvin wave straddling the equator in the Indian Ocean on Day 8. The southern lobe of the wave is actually a 958mb tropical cyclone on the GFS, at 7.5°S no less, and in May. I would love to see this.

Levi do you think the -NAO will allow more warming above normal over the MDR?

From April 11 - 20, 2013, the ITF experienced an above-average northward advancement across the central portion of West Africa; though it still lagged behind the mean climatological position elsewhere. The mean western segment of the ITF approximated 12.8 degrees North and led the mean position by 0.3 degrees due to an anomalous surge of moist southerly winds across the Gulf of Guinea, bringing moderate to locally heavy rain as far north as Burkina Faso and western Niger. In contrast, the ITF mean eastern portion was located near 8.8 degrees North and simply trailed the average position by 1.1 degrees due to continued intrusion of dry air from the North. Figure 1 shows the current ITF position relative to the climatological average for the second dekad of April and its previous position during the first dekad of April. Figure 2 and 3 are time series, illustrating the latitudinal mean of the western and eastern portion of the ITF, respectively, and their evolutions since the start of April.

Quoting Levi32:I just noticed that the 18z GFS has a super awesome complex that looks like a convectively-coupled Kelvin wave straddling the equator in the Indian Ocean on Day 8. The southern lobe of the wave is actually a 958mb tropical cyclone on the GFS, at 7.5°S no less, and in May. I would love to see this.

Well, at day 8 it's not out in fantasy land yet, getting there but not quite.

Streamlines look divergent right off the LA coast. Do I have this backwards?

Upper-Level Atmospheric Divergence

Background: Using the gridded atmospheric motion vector output u and v AMV components are averaged over the 150, 200, 250, and 300 hPa levels. Divergence is computed using finite differencing of du/dx dv/dy, where u and v are the wind components and x and y are the horizontal grid spacing. In the plots positive divergence values are shown with solid lines, negative values (convergence) are shown with dashed lines.

Quoting TomTaylor:Not that it really matters but I just wanted to point out that the left exit region of the SW jet streak you are looking at is not particularly divergent.

Left exit region is associated with divergence if the jet streak is cyclonically curved. In this case it has some anticyclonic curvature associated with it. As a result, it is not a divergent region. Evidence can be seen observationally by looking at the dry air just to the west of the convection on water vapor. CIMSS analysis also confirms the western GOM is not divergent aloft and on the previous analysis even had a convergent signal aloft.

This is true but but dry air in the upper levels on water vapor isn't necessarily related to upper divergence whether lacking or present.

I know he wrote a blog as I am in here almost every day, my comment was in reference to creating a petition..He also did a blog about us signing a petition on Earth day..I was suggesting the same could be done for the NHC employees but WU instead start it this time..heck..I even signed the petition as well..

I just noticed that the 18z GFS has a super awesome complex that looks like a convectively-coupled Kelvin wave straddling the equator in the Indian Ocean on Day 8. The southern lobe of the wave is actually a 958mb tropical cyclone on the GFS, at 7.5°S no less, and in May. I would love to see this.

You would think as many bloggers here and the interest in hurricanes, that someone would have started a petition..we can sign one for GW but not for this immediate threat?..Maybe Dr. Masters or his staff can start one and submit it to the White House (We the People)to where they have to answer it with so many signatures..just a suggestion..

doc did write a blog regarding this issue awhilke back on april 15here is the link

Quoting 1900hurricane:That thing is sitting in two very favorable jet regions; the left exit region of the SW jet streak, and the right entrance region of the NE jet streak. That right entrance region looks particularly divergent.

Not that it really matters but I just wanted to point out that the left exit region of the SW jet streak you are looking at is not particularly divergent.

Left exit region is associated with divergence if the jet streak is cyclonically curved. In this case it has some anticyclonic curvature associated with it. As a result, it is not a divergent region. Evidence can be seen observationally by looking at the dry air just to the west of the convection on water vapor. CIMSS analysis also confirms the western GOM is not divergent aloft and on the previous analysis even had a convergent signal aloft.

I'm totally not trying to bring up climate change with this statement, but the weather this year is just...different. I'm not sure if I recall a spring like this one, but I've only been around 25 years. It just seems like the overall pattern is atypical with large cut-off upper low pressure systems, no severe weather (compared to norm), and blizzards w/ record cold in the Plains/Midwest.

We have many USA weather companys plus every country has there own weather company.Weather Underground, Accue Weather ,Weather Chanel, then we have the canadian model, the Eruo model wish is a very good forcast model and in the event of tornado breakouts we have lots of chaser who keep us informed on the ground

PLEASE, we implore you to contact your Congressman and Senators to put a stop to this. NWS is in dire straits should this furlough occur. They are already short staffed with some offices down 4 and 5 forecasters, and other positions that have not been filled in nearly 2 years. Unbelievable! Please share, send to your local media etc. This need to be a grass roots effort. Please help now.

I,m not a American but if your goverment is trying to fix there financial problems then support them other wise your children will have to suffer greater consequences. We could do without them for a entire year

PLEASE, we implore you to contact your Congressman and Senators to put a stop to this. NWS is in dire straits should this furlough occur. They are already short staffed with some offices down 4 and 5 forecasters, and other positions that have not been filled in nearly 2 years. Unbelievable! Please share, send to your local media etc. This need to be a grass roots effort. Please help now.

You would think as many bloggers here and the interest in hurricanes, that someone would have started a petition..we can sign one for GW but not for this immediate threat?..Maybe Dr. Masters or his staff can start one and submit it to the White House (We the People)to where they have to answer it with so many signatures..just a suggestion..

PLEASE, we implore you to contact your Congressman and Senators to put a stop to this. NWS is in dire straits should this furlough occur. They are already short staffed with some offices down 4 and 5 forecasters, and other positions that have not been filled in nearly 2 years. Unbelievable! Please share, send to your local media etc. This need to be a grass roots effort. Please help now.

Our blob won't move West.. but maybe it will throw off some rain bands before it strengthens and heads East.. strange to be looking at a proto-cyclone this early. I guess the season is officially kicked off.

"Scattered storms will continue to randomly develop through the evening. Some small hail, gusty wind, lightning and heavy rain will occur. Activity should taper down later this evening before more storms may fire in the morning," said Bay News 9 Meteorologist Josh Linker.Heavy rain and storms moved across the area early Tuesday, leading to more than three inches of rain in some areas.

Rain totals on Davis Islands and in Valrico were more than three inches. Two inches fell in Tampa, Dunedin and Land O' Lakes. New Port Richey saw just below two inches while most of Polk County had about an inch of rainfall.Linker said another pattern is moving our way in the Gulf of Mexico."It's kind of an unusual pattern but we'll take the rain any time we can get it this time of year," he said.A trough in the west is going to keep our rain chances going for the next couple of days. That same trough will bring chilly air into the central part of the country. It could cause record lows into Texas.

Those extreme lows won't reach us but our temperatures will cool down eventually.

Overnight into Wednesday, it will mostly be clear. But there is a good chance that there will be showers on Wednesday and even Thursday. The showers for Thursday won't likely be in the morning but during the day.

For the rest of Tuesday, there is a 20 percent chance of rain. Those odds climb up to 60 percent on Wednesday and then there's a 50 percent chance on Thursday.

Right now, you can expect the weekend highs to be in the 80's with a 50 percent chance of rain for Saturday

Out and about today, was thinking about what a late spring it is this year. Being in the UK for 13 years, haven't seen it this late. May 1st now....And the trees are 'just' starting to leave, the daffodil's are all finally in bloom (after some had started early end of Jan at the early part of winter being mild, but then stalled and froze up and nothing finished til last few weeks). We've been hitting round 50'. Felt like a beach day in the sun today after the months of freezing temps (and not even close to you there!).

Been too busy to really enjoy the nice days we've had though! Did clear up at right time for full moon/lunar eclipse last week and set up camera with telescope mounted...but was too much cloud on the horizon, missed it!

late springs normally means short summers tonight its may 1 4 months of nice weather before the sept chill starts to return

I've been to Guatemala in mostly high terrain where it was a relatively cool tropical climate because of the high elevation. I would not want to to live in a place that gets a heat index that high, that's insane combination of heat and high dew points.

Guatemala city usually has nice weather i love it there to but i love Belize to you get used to the intense heat

.NOW...SLOW MOVING SHOWERS AND LIGHTNING STORMS WILL LINGER ACROSS LAKECOUNTY...SOUTHERN VOLUSIA COUNTY AND AROUND METRO ORLANDO THROUGHLATE EVENING. LOCALLY HEAVY RAINFALL AMOUNTS TO AROUND TWO INCHES...GUSTY WINDS TO 40 MPH AND OCCASIONAL CLOUD TO GROUND LIGHTNINGSTRIKES CAN BE EXPECTED. SHOWER AND THUNDERSTORM ACTIVITY HAS ENDEDACROSS OKEECHOBEE COUNTY AND THE TREASURE COAST.

Quoting belizeit:The highest Heat Index ever recorded was 172 F with global warming adding more moisture to the atmosphere that record could soon be broken

I've been to Guatemala in mostly high terrain where it was a relatively cool tropical climate because of the high elevation. I would not want to to live in a place that gets a heat index that high, that's insane combination of heat and high dew points.